Automotive brake



July 15, 1924. v 1501,159

J. R. BARTHOLOMEW AUTOMOTIVE BRAKE Filed 001;. 4, 1922 INVENTOR JOHN R. BARTHOLOMEW ATTORNEY ually operated -means for side of the diaphragm Patented July 15, 1924.

HOUSE AIR BRAKE COHYANY, O1 WILIERDING, rmmsynvam A ml-EHO! auroxo'nvn tenan Application ma 9mm 4, 1922. Serial in. mm.

This invention relates to brakes for motor vehicles, and more particularly to a comb and fluid pressure brake.v

blned mechanical The principalrobject of my invention is to provi e a fluid pressure brake and mancontrolling the brakes mechanically and for also controlling ressure brakes.

Other jects and advanta in the following more detai of the invention.

In the accompanying drawing, the single figure is a diagrammatic view,partly in section, of a motor vehicle brake equipment embodying my invention.

As shown in the drawing, the brake equipment may comprise one or more brake chambers 1 each containing a flexible dia hragm (-not shown) adapted to be operated y fluid under pressure for projecting-a push rod 2. The push rod 2 may be connected to an equalizing bar 3 having its ends pivotally connected to pull rods 4 through which the brakes of the motor vehicle are applied and released.

For controlling the fluid pressure brakes, a valve device may 'be provided comprising a casing 5 having a diaphragm chamber containing a flexible diaphragm 6. A stem 7 carried by the diaphragm 6 is adapted to operate a release slide valve8 and a supply 10 acts against one valve 9. A coil spring and isengaged by es will appear ed description a movable member 11.

A lever 12, pivotally mounted on the supporting bracket 13, engages the member 11, so that movement of the lever -operates the member 11 to compress the s ring 10. A pedal lever 14, which may be t e foot operated lever usually employed for operating the brakes mechanically, is connected through a link 15 with a pull rod 16 for operatin the brakes mechanically and with a pul rod 17 which is pivotally connected to the Ilfmiir 12 for controlling the fluid pressure ra es.

I The rod 16 is operatively. connected'to sure . chambers 1.

the ing e ongated slots 19' in win pin 20 carried by the bar-3.

f it is desired to apply the braliee the pedal lever 14 the operator, causing-a forward movement of the pull rod 17, so that lever 12 depresses the member 11, com ressing the spring 10. Diaphragm 645; t en operated ring 10 to open the mit fluid under presfrom a reservoir 21-, containing fluid under pressure, through pipe 22 to the brake y the pressure of s supply valve 9 and a chambers 1 are thereupon operated to pro- 'ect the ush rods 2, moving the equalizing ar 3 and the pull rods 4 to a ply the brakes.

It will be noted that wiiile the initial movement of the dal lever 14 operates the pull rod 16 as weil as the rod 17 the movement of the rod 16 is not efl'ective to apply the brakes mechanically, since the tion movement due to the slots 19 in the yoke 18 prevents the transmission of power from the rod 16 to the bar 3. When the brakes are applied by fluid pressure the equalizing bar 3 moves forward and the slots 19 permit relative movement of said bar with respect to the rod 16, so that the rod 16 cannot be moved forward and thus cause a further forward movement of the rod 17 and the lever 12, which of course would cause a further compression of s ring 10 and a further supply of fluid to the rake chambers when not lntended.

It will also be noted that the forward movement of the equalizing bar 3 causes the forward movement of pin 20 in the slots 19, so that further lost motion is provided in case the pedal lever 14 is further depressed to appl the fluid pressure brakes with increased orce, without-causing a me-v chanical movement of the e ualizing bar 3 by the further movement of t e pull rod 16.

If, for any reason, the fluid pressure brakes should fail to act when the pedal lever is depressed, then as soon as the lost motion due to the slots 19 at the rear of pin 20 is taken up, the continued de ression of the pedal lever 14 will operate through the pull rod 16 to actuate the equalizing bar 3 and thus appl the brakes mechanically.

By reason 0 the above described construction it will be seen that while the same manually operated mechanismis employed for ualizing bar 3 through a yoke 18 havis depressed by the rates: I

lost mo-' The diaphragms in the brake 2.. 11 an automotive brake, the combinacontrolling the brakes mechanically and by fluid under pressure, the o erator 1s only re uired .toj pre'ss the peda lever with a light force, merely sufiicient to operate the lever 12, so long as the fluid pressure bralre is operative. On the other hand, if the fluid ressuref brake should fail, the brakes will i.- applied mechanically by the movement of the same pedal lever. k p

It will be understood that the manual control may be Ieflected by mechanism adapted to be operated either by the hand or the foot of the operator.

Having now described my invention, what I claim as new and desire to secure byLetters Patent, is

"1. luau-automotive brake, the combination with a fluid pressure brake, of manually operable means adapted upon initial movement to apply the fluid pressure brake and means for a plying the brakes mechanically upon a a rther movement of said manually operable means only in case the fluid ressure brake fails to act.

tion with a brake applying member, fluid pressure means for operating said member, mechanical means for operating said memher, and manually operable means for controlling said fluid pressure means andsaid mechanical means, of means fonnormally preventing the operation of the mechanical means b said manually operable means during t e initial movement of said manually operable means.

' 3. In an automotive brake, the combinamechanically operated member for operating said brake applying member, of a lost motion connection between said brake ap- 4 plying member and said mechanically operated member for permitting movement 0- said mechanically operated member relative to the brake applying member and movement of the brake ap lying member relative to the mechanical o erated member.

4. In an automotive ra e, the combination'with a brake applying member and a mechanically operated member for operating said brake applying member, of a lost motion connection between said brake applying member and said mechanically operated member for permitting movement of said mechanically operated member relative to the brake a ply ng member and movement of the bra e applying member relative to the mechanically operated member, and fluid pressure means for also operating said brake applying member.

5. In an automotive brake, the combination with a brake applying member and a manually operable mom or for mechanically operating said brake applying member, of means permitting movement of said brake applyin member relative to said manually operate member and movement of said manually operated member relative tosaid brake applyin member and fluid pressure means oontro ed by said 'manually operable member for alsooperating said brake 7 applying member.

In testimony whereof I have hereunto set.

,my hand. tion with a brake applying member and a I JOHN B. BARTHOLOMEW. 

